Transient (toxic) synovitis

Background

• Self-limiting inflammatory process of the hip
• Most common cause of acute hip pain in children <10yr
  • Peak incidence 3-8yrs, with a mean of 6 yrs
• Male:Female is 2:1
• Usually unilateral
• 32-50% present after recent viral URI
• Possible posttraumatic or allergic pathologies

Clinical Features

• Abrupt onset of unilateral hip pain, limp, and restricted hip motion
• Nontoxic appearance
• May have a low grade fever

Differential Diagnosis

Pediatric limp

Hip Related

• Acute rheumatic fever
• Developmental dysplasia of hip
• Femur fracture
• Juvenile idiopathic arthritis
• Legg-Calve-Perthes disease
• Septic arthritis of the hip (peds)
  • Lyme disease arthritis
• Slipped capital femoral epiphysis
• Transient (toxic) synovitis
• Osteosarcoma

Other Causes of Limping

• Developmental dysplasia
• Fracture
  • Toddler's fracture
  • Tillaux fracture, adolescent
• Neoplasm:
  • Leukemia
  • Ewings
  • Osteogenic sarcoma
  • Metastatic neuroblastoma
• Osteomyelitis
• Myositis
• Other:
  • Appendicitis
  • Meningitis
  • Epidural abscess (spinal)

Evaluation

Work-up

• X-ray if suspicious for fracture
• Plain films or ultrasound can show effusion
  • If effusion found consider arthrocentesis
  • Presence of effusion does not rule in or out transient synovitis as bilateral effusions can occur in 25% of children

Evaluation

Must distinguish from septic arthritis

• Transient Synovitis favored by:
  • Temperature <38.5
  • ESR <20
  • WBC <12,000
  • CRP <2
• Septic arthritis favored by:
  • Temperature >38.5
  • ESR >40
  • WBC >12,000
  • CRP >2
  • severe pain with ROM
  • Kocher Criteria for septic hip
    • 4 criteria: non-weight bearing, ESR>40, WBC>12,000, fever
    • 4/4 99% probability of septic hip
    • 1/4 3% probability of septic hip

Management

• Return to full activity as tolerated
• NSAIDs

Disposition

• If diagnosis is certain, follow up with primary care provider within 1 week as needed

See Also

• Hip Pain
• Hip Pain (Peds)